Vaccines & Viral Mutations

[deesalie]

Does anyone have any solid info on whether the use of vaccines have contributed to the mutation of viruses?

Nirvana, I'm told you're in research mode atm :D

[Nirvana]

Nirvana, I'm told you're in research mode atm :D

Aren't we all Dee? ;)

Well I don't have much on my disk at this point but whatever I have, I will put it up.

http://www.harvardscience.harvard.edu/medicine-health/articles/mutation-reported-aids-vaccine

http://www3.interscience.wiley.com/journal/112192064/abstract?CRETRY=1&SRETRY=0
The excretion of virus by 30 children was followed over a period of 28 days after their first vaccination with live oral poliovaccine. The type 1 and type 2 strains were isolated at similar high frequencies throughout this period, while the type 3 strain was not excreted by most children after day 2 post vaccination. Mutations in the 5http://www3.interscience.wiley.com/giflibrary/12/prime.gif non-coding region associated with the attenuated phenotype reverted most rapidly for type 3 and least rapidly for type 1. The data are consistent with different degrees of selection against the attenuating mutations in the three serotypes in the gut, but imply that reversion is required for prolonged excretion. The findings also provide a possible explanation for the reported distribution of the rarely occurring vaccine associated cases between recipients and contacts for the three serotypes. A statistically significant difference was not observed between vaccine from the two main suppliers to the UK market.

http://www.pedresearch.org/pt/re/pedresearch/abstract.00006450-199209000-00002.htm;jsessionid=KxhWcynWbxwltlH9yqJ3DQnMt60gL mnBRkYYfy1wLGvBJDcfBs2G!713060492!181195629!8091!-1
A variant of hepatitis B virus (HBV) having a specific mutation within the S gene has been found to infect vaccinees. To know whether similar variants were involved in Japan, we analyzed two cases of maternal transmission of HBV in infants immunized with hepatitis B immune globulin and hepatitis B vaccine. DNA clones of HBV S genes were propagated from patients and family members and sequenced. In one family, the DNA clones from the baby patient had a Gly-to-Arg mutation at the 145th codon of the S gene, whereas those from her mother had no such mutations. In the other family, all the DNA clones obtained from the two infected children had the 145th codon intact, but they had a missense mutation at the 126 th codon of the S gene, causing an amino acid substitution of Asn for Thr or Ile. This same mutation was observed in 12 of 17 clones of DNA obtained from their mother. In comparison with the wild type HBV-derived hepatitis B surface antigen, the two types of S gene mutations, either at the 145th or the 126th codon, were associated with a significant decrease in the antigenicity of some determinants on the hepatitis B surface antigen, measured by MAb. Amino acid substitution at these sites, therefore, would have induced the escape from conventional vaccines that were S gene products of wild type HBV and also from hepatitis B immune globulin, whose main components were probably also antibodies against the S gene products expressed by wild type HBV.

http://medind.nic.in/icb/t06/i9/icbt06i9p803.pdf
Hepatitis B virus mutation in children.

http://www.newsrx.com/newsletters/Vaccine-Weekly/2004-09-22/0922200433348VW.html
Hepatitis C virus mutation affects proteasomal epitope processing


http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T1B-405SNJ5-11&_user=1790654&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000054312&_version=1&_urlVersion=0&_userid=1790654&md5=572c8b14172ccedc4687a19dc6781085

Effect of hepatitis B virus mutants on efficacy of vaccination


http://arjournals.annualreviews.org/doi/abs/10.1146%2Fannurev.micro.51.1.151
RNA VIRUS MUTATIONS AND FITNESS FOR SURVIVAL
RNA viruses exploit all known mechanisms of genetic variation to ensure their survival. Distinctive features of RNA virus replication include high mutation rates, high yields, and short replication times. As a consequence, RNA viruses replicate as complex and dynamic mutant swarms, called viral quasispecies. Mutation rates at defined genomic sites are affected by the nucleotide sequence context on the template molecule as well as by environmental factors. In vitro hypermutation reactions offer a means to explore the functional sequence space of nucleic acids and proteins. The evolution of a viral quasispecies is extremely dependent on the population size of the virus that is involved in the infections. Repeated bottleneck events lead to average fitness losses, with viruses that harbor unusual, deleterious mutations. In contrast, large population passages result in rapid fitness gains, much larger than those so far scored for cellular organisms. Fitness gains in one environment often lead to fitness losses in an alternative environment. An important challenge in RNA virus evolution research is the assignment of phenotypic traits to specific mutations. Different constellations of mutations may be associated with a similar biological behavior. In addition, recent evidence suggests the existence of critical thresholds for the expression of phenotypic traits. Epidemiological as well as functional and structural studies suggest that RNA viruses can tolerate restricted types and numbers of mutations during any specific time point during their evolution. Viruses occupy only a tiny portion of their potential sequence space. Such limited tolerance to mutations may open new avenues for combating viral infections.

[ema-adama]

Here's another one for Polio


BACKGROUND: Poliovirus rapidly evolves by nucleic acid substitutions and genetic recombination with other polioviruses and non-polio enteroviruses. Evolving oral poliovaccine can rapidly revert to neurovirulence and undergo antigenic alterations. OBJECTIVES: To evaluate the threat of vaccine-derived poliovirus (1-15% divergence from the respective Sabin strain) for a poliomyelitis-free population in a country with a long-standing routine vaccination program. METHODS: We characterized genetic and antigenic changes in OPV (Sabin) strains isolated from sewage in Israel and evaluated intestinal immunity by measuring fecal excretion after OPV challenge of vaccinated children. RESULTS: Characterization of poliovirus from sewage revealed eight type 2 and three type 3 vaccine polioviruses that had replicated and started to evolve (vaccine that replicated and diverged by 0.5 to < or = 1.0%) and nine highly diverged type 2 vaccine-derived polioviruses (1-15% divergence from the respective Sabin strain) with 8-14% divergence between the years 1998 and 2005. Six of the eleven VRPV uniquely recombined with OPV and/or NPEV. The nine VDPV were epidemically related, genotypically neurovirulent, and had 10-15 amino acid substitutions in antigenic sites altering their antigenicity, but shared a single recombination. Type 2 OPV was excreted by 23% and 17% of infants challenged with OPV 3 months after partial immunization (two doses each of OPV and enhanced inactivated poliovirus) or full immunization (three doses of each) respectively, despite high humoral antibody titers. CONCLUSIONS: Our findings, which show that OPV is excreted for a significant period by children with high humoral immunity, emphasize the long-term potential threat from VDPV in highly vaccinated populations. An adequate immunization program, combined with environmental surveillance, is necessary to prevent poliomyelitis and community transmission of poliovirus.
PMID: 16805227 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www.ima.org.il-imaj-dynamic-web-img-imaj.gif (http://www.ncbi.nlm.nih.gov/entrez/utils/fref.fcgi?PrId=6673&itool=AbstractPlus-nondef&uid=16805227&db=pubmed&url=http://www.ima.org.il/imaj/dynamic/web/ArtFromPubmed.asp?year=2006&month=05&page=312)
I love that this is from the same hospital where Step MIL works - the SMIL who sneers are me every time vaccines are mentioned.... And freaks out about polio in South Africa, while obviously missing what is right here in Israeli sewers :giggle:

[deesalie]

Aren't we all Dee? ;)


too true

Thanks for all this info :D